ROADSIDE AND GARAGE.
Page 69
If you've noticed an error in this article please click here to report it so we can fix it.
Interesting Contributions • Mechanic from Our Driver and Readers.
An Improvised Expanding Reamer.
rr is true that every well-equipped 'repair shop should have a complete set of expanding reamers, but, unfortunately, this is not always the case; consequently many mechanics have to do the best they can. A correspondent, " C.H.D.," of Rhyl, tells us how he has made for himself a set of expanding reamers, which he finds most useful, as by adding slips of paper between the blade and the body he can adjust to very fine limits the diameter of the hole to be produced.
His method is to procure a piece of half-round steel of a suitable size to lie in the hole to be reamered, as shown in sketch. He then takes an old file, or a piece of cast-steel—he prefers a file, as it is already hardened. Be softens the ends so that they can be drilled, and he fits steady pins for clamping the file to the half-round steel. He then grinds all the teeth off the file and bevels the edges as shown. Should the result be a hole that is not quite as large as required, he packs up the cutter from the half-round bed by inserting slips of paper. We should have *• thought that better results would be obtained by making only one edge of the cutter sharp, and rounding off the other edge so that it did not act as a cutter, and helped to position the working edge, so preventing chatter and i enabling a better finish to be obtained.
Engine Lubrication.
THAT most trouble with big-ends run ning out is experienced during the hours of darkness has been noticed by a correspondent, " R.P.," of Grimsby, who attributes this to the fact that at night one cannot watch the indicator which shows the pressure or flow of oil being delivered to the engine.
To remedy this he suggests that a light should he provided so that by pressing a button a driver can see at a glance what is going on with his lubrication system.
In his case he is interested in a Tyler .T.B.4 engine, but his plan applies equally wall to any kind of indicator. He fixes a small bulb in such a position that it will illuminate the indicator, and by means of a simple switch and a pocket battery he is able to in spect his indicator at all times. • Considering the importance of being able to see the indicator during the dark hours, it is curious that such a device as this should be left to the ingenuity of the driver, when it would he naturally expected to be part of the work of the designer. This is especially the case when we recollect that more than 20 years age indicators which could be seen plainly at night Neste fitted as a standard to one make of lorry.
Big-end Design.
THAT the diseuasion relating to bigends still interests our readers we feel sure by the number of letters on the subject we are still receiving. A correspon dent, " of East Coshate,
Hants, who has had 21 years' experience with all Sorts of lorries, is in favour of the type of connecting rod and big-cad bearing adopted on the Mandslay. In this Construction the rod is hollow and tapering.
The points he raises in favour of this pattern of rod and bearing are as follow: (I-) The rod being hollow retains oil and answers as a reserve storage while the engine is being warmed up, or should the supply of oil fail through any cause the rod will hold enough to enable a driver to carry on for a few miles. (2) The bearing is rigid, and there are no shells to work loose ; also it is easily taken up for wear.
A Remedy for Sticking .Valve Stems.
ONE of our correspondents, of Bishop Auckland, who has been driving a Chevrolet one-ton van, has had trouble through the stems of the valves stieking„ with the result that the exhaust valves burnt away around the seating. On two OPCSSiODS he had a head break off, so he made a search for the cause of the trouble and devised a remedy.
He found that if he filled the it troughs too high it caused an unpleasant overflowing of oil ; so to lubricate the valve stems without oil escaping he procured some soft, round lamp wicks which he arranged so that they would act as lubricators, sucking the oil up by capillary attraction. He wound the wick around each stem and allowed the ends to dip in the troughs ; he then replaced the springs and collars in the usual manner, and every time a spring is compressed it squeezes a little oil on to the stem.
He tells us that after running every day for nine mouths he has had no further trouble with his valves.
He also tells us that he has made a very simple tool for grinding-in his valves by taking an old valve and drilling the present holes in the head right through and fitting pins which project about in. to fit the holes in the valves to be ground. He holds this tool in an ordinary carpenter's brace while grinding. A tool of this pattern was recently illustrated in our page devoted to Ford tips. It would not apply to valves with slotted heads.
A Useful Valve Tip.
VALVES that stick in their guides will • sometimes give 'much trouble when they are •to be removed, as there is a risk of damage to various parts if extreme force be used with a jemmy or crowbar ; there is also a risk of bending the valve stem, which will result in making the valve more difficult than ever to remove.
Trouble of this kind has been experieneed by a correspondent, " J.R.G.," of Battersea, who has found a simple way of overcoming it. He removed the cotter and allowed the tappet to lift the valve to its highest position. Re then procured a piece of round steel of slightly less diameter than the valve stem and cut a piece from it of such a length that it raised the valve one step higher when the tappet rose next time. By cutting pieces of a different length each time he was able to force the valve right up until he could get hold of tho head to remove it.
He had, of course, well soaked the stem with paraffin before using force to extract it.